Semiconductor devices such as bipolar transistors are used for many applications. Bipolar transistors often have insufficient emitter efficiency due to process variations. For example, lateral misalignment between the emitter contact and the emitter results in a reduction of the lateral emitter width which can lead to an increased recombination rate at the emitter contact. The closer the emitter contact is to an edge of the emitter, the higher the recombination rate. A high recombination rate also deteriorates the emitter efficiency and reduces the gain of the bipolar transistor. Furthermore, other transistor parameters can also vary. Typically, laborious design rules are required in an attempt to compensate these effects, for example by increasing the used chip area which also increases the production costs.